A loan is a contract between a borrower and a lender in which the borrower receives an amount of money (principal) that they are obligated to pay back in the future. Most loans can be categorized into one of three categories:

Amortized Loan: Fixed payments paid periodically until loan maturity
Deferred Payment Loan: Single lump sum paid at loan maturity
Bond: Predetermined lump sum paid at loan maturity (the face, or par value of a bond)

Amortized Loan: Paying Back a Fixed Amount Periodically
Use this calculator for basic calculations of common loan types such as mortgages, auto loans, student loans, or personal loans, or click the links for more detail on each.